Stratosphere winds affect ocean circulation, climate

Washington: Winds 15-30 miles high up in the stratosphere change mile-deep ocean circulation patterns, affecting earth`s climate in turn, says a new study.

"We found evidence that what happens in the stratosphere matters for the ocean circulation and, therefore, for the climate," says Thomas Reichler, study co-author and associate professor of atmospheric sciences from the University of Utah.

Scientists already knew that events in the stratosphere, six to 30 miles above the earth, affect what happens below in the troposphere, the part of the atmosphere from earth`s surface up to 32,800 feet. Weather occurs in the troposphere, the journal Nature Geoscience reports.

Researchers also knew that global circulation patterns in the oceans - patterns caused mostly by variations in water temperature and saltiness - affect global climate, according to an Utah statement.

"It is not new that the stratosphere impacts the troposphere," says Reichler. "It also is not new that the troposphere impacts the ocean. But now we actually demonstrated an entire link between the stratosphere, the troposphere and the ocean."

Reichler and colleagues used weather observations and 4,000 years worth of supercomputer simulations of weather to show a surprising association between decade-scale and periodic changes in stratospheric wind patterns known as the polar vortex, and similar rhythmic changes in deep-sea circulation patterns.

Reichler conducted the study with Utah doctoral student Junsu Kim, and with atmospheric scientist Elisa Manzini and oceanographer Jurgen Kroger, both with the Max Planck Institute for Meteorology in Hamburg, Germany.